dental materials 32S (2016) e1–e103 e25 Fig. 1 were statistically analyzed with 2-way ANOVA and Tukey’s multiple comparison (˛ = 0.05). Results: Generally, the MPS of all groups increased with an increase of applied load. The MPSs at 200-N load were summa- rized in Fig. 1. The locations of MPS ranking were EP > IP > MP for Cont, IP > MP = EP for FRP, and IP > EP = MP for Co-Cr and zir- conia. Regarding EP and IP, Cont were significantly greater than the others. Although the thickness of palatal part of frame- works was half of that of Cont, the MPS with the framework was smaller than that without framework. The MPS of zirco- nia and Co-Cr showed a similar tendency probably because of their similar elastic modulus. Due to interwoven fiber- glass layered structure, this FRP material showed anisotropic mechanical properties. Therefore stress distribution pattern of the FRP was different form the others. Conclusions: Within the limitation of this study, the frame- work fabricated with CAD/CAM systems significantly reduced the deformation of the maxillary complete denture. http://dx.doi.org/10.1016/j.dental.2016.08.048 48 Liposome adsorption to restorative materials S. Nguyen 1,2 , M. Adamczak 2 , M. Hiorth 2 , G. Smistad 2 , H.M. Kopperud 1,∗ 1 Nordic Institute of Dental Materials (Niom), Norway 2 School of Pharmacy, University of Oslo, Norway Purpose/Aim: To investigate the in vitro adsorption and retention of liposomes onto four common types of dental restorative materials. Materials and methods: Uncoated liposomes (positively and negatively charged) and pectin coated liposomes (low- and high-methoxylated) were prepared and characterized in terms of particle size and zeta potential. Four common restorative materials were included: conventional (Tetric Evo- Ceram) and silorane-based (Filtek Silorane) resin composites, as well as conventional (Fuji II) and resin-modified (Fuji II LC Improved) glassionomer cements (GIC). The adsorption of liposomes was performed by immersion, quantified by fluo- rescence detection, and visualized by fluorescence imaging and atomic force microscopy. Results: Positive liposomes demonstrated the highest adsorption on all four types of materials likely due to their attractive surface charge. They also retained well (minimum 40% after 60 min) on both conventional resin composite and GIC even when exposed to simulated salivary flow. Although an intermediate initial level of adsorption was found for the pectin coated liposomes, at least 70% high methoxylated- pectin coated liposomes still remained on the conventional resin composite after 60 min flow exposure. This indicates significant contribution of hydrophobic interactions in the prolonged binding of liposomes to resin composites. Conclusions: Based on these results, two new possi- ble applications of liposomes in the preservation of dental restorations are suggested: (1) liposomal adsorption may inhibit, reduce, or delay the harmful effects of bacterial adherence and the development of biofilm on the restorative materials and (2) liposomal retention may seal marginal gaps at the tooth tissue-dental material interface preventing micro- leakage. http://dx.doi.org/10.1016/j.dental.2016.08.049 49 Effects of acidity of “Bissap” (Hibiscus sabdariffa) on dental ceramics B. Akon-Laba ∗ , J.C. Ncho-Kamon, E.L.E. Didia, G.T. Maroua Université Félix Houphouet-Boigny, School of Dentistry, Abidjan, Côte D’Ivoire Purpose/Aim: Various studies showed the effect of pH variations from oral environment on dental ceramics. This environment can be modified by foods and drinks consump- tion. Studies showed evidence of ions releases in acidic medium especially in presence of acetic acid whose pH is near commonly consumed drinks. “Bissap,” an acidic drink widely consumed in Côte d’Ivoire is obtained from Hibiscus sabdariffa flowers’ infusion. The purpose of this study is to analyze ions releases after ceramics immersion in “Bissap” and determine the impact of glazing. Materials and methods: 96 ceramic disks were manufac- tured from 2 types of ceramics. Each type is subdivided into 2 groups: with glazing and glazing-free. After pH measure- ment from “Bissap”, the ceramic samples are immerged in it. Sodium, potassium and aluminum ions are dosed by spec- trometry at T 0 , after 24 h, 48 h, 72 h, then after 7 days, 14 days, 21 days and 28 days. Then, we have renewed each bath by adding, every day, 60ml of bissap in the initial bath. The “Bis- sap” solution pH is also measured. Results: The results showed an increase of pH which tends to stabilize upon the 2nd day. One-way repeated ANOVA, showed the following results: The composition of the juice of the different groups of ceramics immersion showed no signif- icant difference (p > 0.05) compared to initial bissap juice, after